An endo-9-azabicyclo[3.3.1]nonan-3-ol derivative is a useful compound applicable as an agrochemical or medicinal intermediate (Patent Document 1). Patent Document 1 discloses that endo-9-benzyl-9-azabicyclo[3.3.1]nonan-3-ol is synthesized by reducing 9-benzyl-9-azabicyclo[3.3.1]nonan-3-one in a methanol solvent with sodium borohydride. However, there is no report disclosing study to reduce an azabicyclo nonane compound in the presence of a ruthenium catalyst.